The present invention relates to a softener composition.
Most of the commercially available merchandise as a softener composition for fibers are compositions comprising a quaternary ammonium salt containing two long-chain alkyl groups in one molecule and being typified by a di(long-chain alkyl) dimethyl ammonium chloride.
However, the quaternary ammonium salt described above suffers from the problem that, when residues thereof after a treatment is discharged into the environment such as a river, most of them are accumulated without biodegradation.
As an improved product against the above-mentioned problem, N-methyl-N,N-bis(long-chain alkanoyloxyethyl)-N-(2-hydroxyethyl)ammonium methyl sulfate, N,N-dimethyl-N,N-bis(alkanoyloxyethyl)ammonium chloride or the like is commercially available. Although the biodegradability of the improved product is improved as compared with that of the quaternary ammonium salt described above, the improved product cannot be said to be a base for sufficiently satisfying a softening effect.
For example, JP-A 10-212665 discloses a softener composition comprising a specific tertiary amine compound or a neutralized or quaternary product thereof.
Accordingly, the object of the present invention is to provide a softener exhibiting an excellent softening effect and a satisfactory biodegradability.
The present invention provides a softener composition comprising the following components (A) and (B):
(A) an amine represented by the formula (I), a salt thereof with an acid or a quaternary product thereof, or a mixture thereof: 
wherein R1 represents an alkyl or hydroxyalkyl group having 1 to 4 carbon atoms, xe2x80x94(CmH2mO)pxe2x80x94H or xe2x80x94(CmH2mO)pCOR3; R3 represents a linear or branched alkyl or alkenyl group having 5 to 35 carbon atoms; when R1 is the alkyl or hydroxyalkyl group having 1 to 4 carbon atoms, q is a number selected from 2 to 60; when R1 is xe2x80x94(CmH2mO)pxe2x80x94H or xe2x80x94(CmH2mO)pxe2x80x94COR3, p is not less than 1 and q is not less than 2, provided that the sum of p and q equals 3 to 60; m and n are the same or different and represent 2 to 6; and m in the number of p and m in the number of q may be the same or different; and
(B) a quaternary ammonium salt represented by the formula (II): 
wherein R4 represents an alkyl group having 1 to 3 carbon atoms; R5 and R6 are the same or different and represent an alkyl group having 1 to 3 carbon atoms, xe2x80x94CnH2nOH or xe2x80x94CnH2nOCOR3; Xxe2x88x92 represents an anion; and n and R3 have the same meanings as defined above.
Further, the present invention relates to use of the above-described composition as a softener. In addition, the present invention relates to a method for softening an article made of fibers with the above-described composition.
In the component (A) used in the present invention, it is preferable that n is 2 or 3, m is 2 or 3 and R3 is an alkyl or alkenyl group having 11 to 21 carbon atoms. When the component (A) is a salt with an acid, the acid used may be an inorganic or organic acid, but hydrochloric acid, sulfuric acid, citric acid and glycolic acid are preferable. With regard to the quaternary product, a quaternarizing agent therefor is preferably methyl chloride, dimethyl sulfate or diethyl sulfate.
The amine represented by the formula (I) is produced for example by mono-amidation of an aminoalkyl alkanolamine such as aminoethyl ethanolamine and then adding at least 2 moles of an alkylene oxide such as ethylene oxide and propylene oxide thereto, followed by esterification of the resultant product; or by cyanoethylating a dialkanolamine such as diethanol amine and diisopropanolamine, hydrogenating the cyanoethylated product in order to be a diamine, then amidation of the resultant product and adding at least one mole of an alkylene oxide, followed by esterification of the resultant product. The esterification may be also carried out prior to or simultaneously with the adding the alkylene oxide.
A fatty acid used in the amidation or esterification is preferably, for example, a coconut fatty acid, a tallow fatty acid, a hydrogenated (or hardened) tallow fatty acid, a palm stearic acid or a hydrogenated palm stearic acid. A lower alkyl ester thereof or a fat and/or oil may be also used. The degree of acylation in total is preferably 1 to 3 and more preferably 1.5 to 2.5.
It is preferable in view of improving the softening effect that the component (B) used in the present invention is one member or a mixture of two or more members selected from quaternary ammonium salts represented by the following formulae (III), (IV) and (V). 
In the formulae (III), (IV) and (V), n is preferably 2 or 3, and R3 is preferably an alkyl or alkenyl group having 11 to 21 carbon atoms and particularly preferably an alkyl or alkenyl group obtained by removing a carboxyl group from a coconut fatty acid, a tallow fatty acid, a hydrogenated tallow fatty acid, a palm stearic acid or a hydrogenated palm stearic acid. It is preferable that R4 is a methyl group and Xxe2x88x92 is a chloride ion or a methyl sulfate ion.
In view of improvement on softening performance or blending stability, the composition of the present invention contains the components (A) and (B) at the ratio of (A)/(B) of preferably from 1/9 to 9/1, more preferably from 4/6 to 8/2 and most preferably from 4/6 to 6/4 by weight.
These components (A) and (B) are preferably formed into the liquid softener by dispersing them in a total amount of 3 to 50% by weight in water. In this case, the components (A) and (B) may be previously mixed and then introduced into water or they may be introduced one after another into water. Alternatively, the respective components may be separately dispersed in water and then mixed.
In order to further improve the dispersibility and/or softening effect, it is preferable that a nonionic surfactant is blended in the composition of the present invention. The nonionic surfactant used is preferably an adduct to a higher alcohol with an alkylene oxide and more preferably an adduct to a C8xe2x88x9222 higher alcohol with 5 to 100 moles, particularly 10 to 60 moles, of ethylene oxide. The blended amount of the nonionic surfactant in the composition of the present invention is preferably 0.1 to 10% by weight.
In addition, a higher alcohol or higher fatty acid can be added in order to further improve a softening performance. A lower alcohol such as ethanol and isopropanol, glycol or polyol as well as an ethylene oxide or propylene oxide adduct thereof can be added as a storage stabilizer. Furthermore, an inorganic salt, a pH adjuster, a hydrotropic agent, a perfume, a defoaming agent, a pigment and the like can be added if necessary.